LEADTOOLS (Leadtools assembly)

CreateAlphaImage Method

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Example 







Leadtools Namespace > RasterImage Class : CreateAlphaImage Method
Creates a grayscale image from this RasterImage alpha channel data.
Syntax
public RasterImage CreateAlphaImage()
'Declaration
 
Public Function CreateAlphaImage() As RasterImage
'Usage
 
Dim instance As RasterImage
Dim value As RasterImage
 
value = instance.CreateAlphaImage()
public RasterImage CreateAlphaImage()
-(LTRasterImage*)createAlphaImage:(NSError**)outError;

public RasterImage createAlphaImage()

 function Leadtools.RasterImage.CreateAlphaImage()

public:
RasterImage^ CreateAlphaImage();

Return Value

The newly create image, which contains the source image alpha channel data.
Remarks

Only 16-, 32-, and 64-bit images can have an alpha channel. If the source image has another color resolution, the result is an image filled with zeros.

Typically, the alpha channel contains a mask that is used for transparency.

For more information, refer to Implementing Transparency.

For more information, refer to Grayscale Images.

For more information, refer to Saving A Region.

Example
Copy Code   
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.WinForms
Imports Leadtools.Dicom
Imports Leadtools.Drawing

Public Sub CreateAlphaImageExample()
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Load the image, at 16 bit per pixel.
   Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1.CMP"), 16, CodecsLoadByteOrder.Bgr, 1, 1)

   ' Specify a rectangle to define the region.
   Dim EllipseRectangle As LeadRect = New LeadRect(image.Width \ 8, image.Height \ 8, image.Width \ 2, image.Height \ 2)

   ' Create an elliptical region in the AlphaImage.
   image.AddEllipseToRegion(Nothing, EllipseRectangle, RasterRegionCombineMode.Set)

   ' Create a mask image from the region.
   Dim alphaImage As RasterImage = image.CreateMaskFromRegion()

   ' Update the alpha channel in the main image.
   image.SetAlphaImage(alphaImage)

   ' Save the image at 16 bits per pixel to keep the alpha channel.
   codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "TestAlpha.TIF"), RasterImageFormat.Tif, 24, 1, 1, 1, CodecsSavePageMode.Overwrite)

   ' Load the bitmap that we just saved and get its alpha channel.
   image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "TestAlpha.TIF"), 16, CodecsLoadByteOrder.Bgr, 1, 1)

   alphaImage = image.CreateAlphaImage()

   ' Use the AlphaBitmap as a mask to set the region in the MainBitmap.
   image.AddMaskToRegion(Nothing, alphaImage, RasterRegionCombineMode.Set)

   image.Dispose()
   codecs.Dispose()
End Sub

Public NotInheritable Class LEAD_VARS
Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.WinForms;
using Leadtools.Dicom;
using Leadtools.Drawing;

      
public void CreateAlphaImageExample()
{
   RasterCodecs codecs = new RasterCodecs();
   // Load the image, at 16 bit per pixel.
   RasterImage image = codecs.Load(Path.Combine(ImagesPath.Path, "IMAGE1.CMP"), 16, CodecsLoadByteOrder.Bgr, 1, 1);
   // Specify a rectangle to define the region.
   LeadRect ellipseRectangle = new LeadRect(image.Width / 8, image.Height / 8, image.Width / 2, image.Height / 2);

   // Create an elliptical region in the AlphaImage.
   image.AddEllipseToRegion(null, ellipseRectangle, RasterRegionCombineMode.Set);

   // Create a mask image from the region.
   RasterImage alphaImage = image.CreateMaskFromRegion();

   // Update the alpha channel in the main image.
   image.SetAlphaImage(alphaImage);

   // Save the image at 16 bits per pixel to keep the alpha channel.
   codecs.Save(image, Path.Combine(ImagesPath.Path, "TestAlpha.TIF"), RasterImageFormat.Tif, 24, 1, 1, 1, CodecsSavePageMode.Overwrite);

   // Load the bitmap that we just saved and get its alpha channel.
   image = codecs.Load(Path.Combine(ImagesPath.Path,"TestAlpha.TIF"), 16, CodecsLoadByteOrder.Bgr, 1, 1);

   alphaImage = image.CreateAlphaImage();

   // Use the AlphaBitmap as a mask to set the region in the MainBitmap.
   image.AddMaskToRegion(null, alphaImage, RasterRegionCombineMode.Set);

   image.Dispose();
   codecs.Dispose();
}
RasterImageExamples.prototype.CreateAlphaImageExample = function ( )
{
   Tools.SetLicense ( ) ;
   with (Leadtools) {
      with (Leadtools.Codecs) {

         var codecs = new RasterCodecs();
         // Load the image, at 16 bit per pixel.
         var srcFileName = "Assets\\Image1.cmp";
         var image;

         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile), 16, CodecsLoadByteOrder.bgr, 1, 1)
         })
            .then(function (img) {
               image = img;

               // Specify a rectangle to define the region.
               var ellipseRectangle = LeadRectHelper.create(image.width / 8, image.height / 8, image.width / 2, image.height / 2);

               // Create an elliptical region in the AlphaImage.
               image.addEllipseToRegion(null, ellipseRectangle, RasterRegionCombineMode.set);

               // Create a mask image from the region.
               var alphaImage = image.createMaskFromRegion();

               // Update the alpha channel in the main image.
               image.setAlphaImage(alphaImage);

               // Save the image at 16 bits per pixel to keep the alpha channel.
               return Tools.AppLocalFolder().createFileAsync("TestAlpha.TIF")
            })
            .then(function (saveFile) {

               var saveStream = LeadStreamFactory.create(saveFile);
               return codecs.saveAsync(image, saveStream, RasterImageFormat.tif, 24, 1, 1, 1, CodecsSavePageMode.overwrite)
            })
            .then(function () {

               image.close();

               // Load the bitmap that we just saved and get its alpha channel.
               srcFileName = "TestAlpha.TIF";
               return Tools.AppLocalFolder().getFileAsync(srcFileName)
            })
            .then(function (loadFile) {
               return codecs.loadAsync(LeadStreamFactory.create(loadFile), 16, CodecsLoadByteOrder.bgr, 1, 1)
            })
            .then(function (img) {
               image = img;

               alphaImage = image.createAlphaImage();

               // Use the AlphaBitmap as a mask to set the region in the MainBitmap.
               image.addMaskToRegion(null, alphaImage, RasterRegionCombineMode.set);
               console.assert(image.hasRegion, "image.HasRegion");

               image.close();
               codecs.close();
            });
      }
   }
}
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Dicom;

      
public async Task CreateAlphaImageExample()
{
   RasterCodecs codecs = new RasterCodecs();
   // Load the image, at 16 bit per pixel.
   string srcFileName = @"Assets\Image1.cmp";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile), 16, CodecsLoadByteOrder.Bgr, 1, 1);
   // Specify a rectangle to define the region.
   LeadRect ellipseRectangle = LeadRectHelper.Create(image.Width / 8, image.Height / 8, image.Width / 2, image.Height / 2);

   // Create an elliptical region in the AlphaImage.
   image.AddEllipseToRegion(null, ellipseRectangle, RasterRegionCombineMode.Set);

   // Create a mask image from the region.
   RasterImage alphaImage = image.CreateMaskFromRegion();

   // Update the alpha channel in the main image.
   image.SetAlphaImage(alphaImage);

   // Save the image at 16 bits per pixel to keep the alpha channel.
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync("TestAlpha.TIF");
   ILeadStream saveStream = LeadStreamFactory.Create(saveFile);
   await codecs.SaveAsync(image, saveStream, RasterImageFormat.Tif, 24, 1, 1, 1, CodecsSavePageMode.Overwrite);

   image.Dispose();

   // Load the bitmap that we just saved and get its alpha channel.
   srcFileName = @"TestAlpha.TIF";
   image = await codecs.LoadAsync(saveStream, 16, CodecsLoadByteOrder.Bgr, 1, 1);

   alphaImage = image.CreateAlphaImage();

   // Use the AlphaBitmap as a mask to set the region in the MainBitmap.
   image.AddMaskToRegion(null, alphaImage, RasterRegionCombineMode.Set);
   Assert.IsTrue(image.HasRegion);

   image.Dispose();
   codecs.Dispose();
}
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Dicom;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Examples;
using Leadtools.Windows.Media;

public void CreateAlphaImageExample(RasterImage image, Stream destStream)
{
   RasterCodecs codecs = new RasterCodecs();
   // Specify a rectangle to define the region.
   LeadRect EllipseRectangle = new LeadRect(image.Width / 8, image.Height / 8, image.Width / 2, image.Height / 2);

   // Create a region in the AlphaImage.
   image.AddRectangleToRegion(null, EllipseRectangle, RasterRegionCombineMode.Set);

   // Create a mask image from the region.
   RasterImage alphaImage = image.CreateMaskFromRegion();

   // Update the alpha channel in the main image.
   image.SetAlphaImage(alphaImage);

   // Save the image at 16 bits per pixel to keep the alpha channel.
   codecs.Save(image, destStream, RasterImageFormat.Tif, 24, 1, 1, 1, CodecsSavePageMode.Overwrite);

   // Load the bitmap that we just saved and get its alpha channel.
   image = codecs.Load(destStream, 16, CodecsLoadByteOrder.Bgr, 1, 1);

   alphaImage = image.CreateAlphaImage();

   // Use the AlphaBitmap as a mask to set the region in the MainBitmap.
   image.AddMaskToRegion(null, alphaImage, RasterRegionCombineMode.Set);

   image.Dispose();
}
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.Dicom
Imports Leadtools.ImageProcessing
Imports Leadtools.ImageProcessing.Core
Imports Leadtools.ImageProcessing.Color
Imports Leadtools.Windows.Media

Public Sub CreateAlphaImageExample(ByVal image As RasterImage, ByVal destStream As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Specify a rectangle to define the region.
   Dim EllipseRectangle As LeadRect = New LeadRect(image.Width / 8, image.Height / 8, image.Width / 2, image.Height / 2)

   ' Create a region in the AlphaImage.
   image.AddRectangleToRegion(Nothing, EllipseRectangle, RasterRegionCombineMode.Set)

   ' Create a mask image from the region.
   Dim alphaImage As RasterImage = image.CreateMaskFromRegion()

   ' Update the alpha channel in the main image.
   image.SetAlphaImage(alphaImage)

   ' Save the image at 16 bits per pixel to keep the alpha channel.
   codecs.Save(image, destStream, RasterImageFormat.Tif, 24, 1, 1, 1, CodecsSavePageMode.Overwrite)

   ' Load the bitmap that we just saved and get its alpha channel.
   image = codecs.Load(destStream, 16, CodecsLoadByteOrder.Bgr, 1, 1)

   alphaImage = image.CreateAlphaImage()

   ' Use the AlphaBitmap as a mask to set the region in the MainBitmap.
   image.AddMaskToRegion(Nothing, alphaImage, RasterRegionCombineMode.Set)

   image.Dispose()
End Sub
Requirements

Target Platforms

See Also

Reference

RasterImage Class
RasterImage Members

 

 

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